The present invention relates to a device for isolating strips, particularly metal strips, conveyed next to one another in their lengthwise direction. These types of devices are used in order to produce a defined horizontal interval between the strips, with which the strips may be fed to further processing. In this way, damage of the strip edges is avoided, which otherwise could be caused by contact between the strips conveyed next one another.
The isolation has particularly significance in the production and processing of metal strips, which are obtained, for example, from a wide metal band by slitting using slitting shears and are subsequently coiled into isolating coils in a coiling device. These types of strips made of metal have a high intrinsic stiffness transverse to the direction of conveyance even if they have a slight thickness. On the one hand, this intrinsic stiffness makes the production of an interval between the individual strips transverse to the direction of conveyance more difficult. On the other hand, due to the intrinsic stiffness of the strips, even slight contacts between the strips may lead to significant damage.
The separation of metal strips is made more difficult if the isolation of the strips is to occur a short distance after the slitting shears. In this case, which occurs frequently due to the overall space available, which is often restricted in practice, the strips which are still connected to the uncut sheet endeavor, due to their intrinsic stiffness, to maintain their original direction of conveyance, so that greater forces have to be applied for the separation.
If, in contrast, the isolation is first performed at a large distance from the slitting shears, the connection to the still uncut sheet does not have such a strong effect. Instead, the danger arises that the strips will run uncontrolled out of the intended direction of conveyance.
In practice, separating devices whose guideways are delimited by separation disks which are fixed in their position are used as a rule. The strips are typically laid by hand into these guideways. Alternatively, isolating the strips through a mechanically-generated, back and forth shaking movement of a separating shaft has also been attempted.
Manual isolation, particularly in the separation of strips made of metal, not only requires great bodily exertion, but also has the danger of injuries. In mechanically-supported isolation, it has been shown that the isolation result of the mechanical back-and-forth movement of the strips is so unreliable that the position of the strips must be corrected by hand. The latter particularly applies for large band thicknesses, in which the intrinsic stiffness of the metallic strips is particularly noticeable.
A device for a separating the front ends of strips produced from a metal band by slitting is known from German Published Application 21 38 088, in which the isolation of the strips is performed using an automatically operating isolating unit. For this purpose, the isolating unit is equipped with clamping devices which are displaceable on a joint axis, to each of which one strip front end is assigned. After the strip front ends are clamped in the clamping devices, the clamping devices are simultaneously displaced on the axis, so that the strip front ends are spread apart from one another like a fan. The movement of the clamping devices along the axis is coordinated in this case via threads having different pitch in such a way that all strip front ends reach their separated positions simultaneously.
The advantage of the known device described above is that it allows automated isolating of the strips within a short operating interval. However, it is disadvantageous that for this purpose a significant constructive outlay is necessary, particularly for the clamping devices. In addition, as a rule the strip front ends may only be laid in the clamping devices when the device is at a standstill. In addition, the known device requires a significant amount of space, which in many cases may only be made available with difficulty.